Java 获得许可后从开始创建一个片段

仅当用户授予存储权限时，我才希望从活动中启动片段。我的主要活动布局如下所示

<FrameLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:id="@+id/root_container"
android:fitsSystemWindows="true"
android:background="@drawable/splash_gradient">
</FrameLayout>

我的get Permissions方法如下所示

    public boolean getPermission() {
    boolean f = false;
    //Check for SDK Version if greater than 23 then seek user permission
    if(Build.VERSION.SDK_INT>=23) {
        //Check whether permission is already granted
        if (ContextCompat.checkSelfPermission(this, Manifest.permission.READ_EXTERNAL_STORAGE)
                != PackageManager.PERMISSION_GRANTED) {
           // Ask for user permission
                ActivityCompat.requestPermissions(this,
                    new String[]{Manifest.permission.READ_EXTERNAL_STORAGE}, 404);
            if(ContextCompat.checkSelfPermission(this, Manifest.permission.READ_EXTERNAL_STORAGE)
                    !=PackageManager.PERMISSION_DENIED)
                f = true;
        }
        else f = true;
    }
    return f;
}

---

当我授予权限时，getPermission返回true，但当第一次运行应用程序时，它在获得getPermission（）方法的结果之前启动片段，当我第二次运行应用程序时，它显示片段布局。

您应该使用

onRequestPermissionsResult

来处理结果：

private static final int REQUEST_CODE = 404;

@Override
protected void onCreate(@Nullable Bundle savedInstanceState) {
    // Your code

    if (savedInstanceState == null) {
        tryToOpenHomeFragment();
    }
}

private void tryToOpenHomeFragment() {
    if (ContextCompat.checkSelfPermission(this, Manifest.permission.READ_EXTERNAL_STORAGE) == PackageManager.PERMISSION_GRANTED) {
        showHomeFragment();
    } else {
        ActivityCompat.requestPermissions(this,
                new String[]{Manifest.permission.READ_EXTERNAL_STORAGE}, REQUEST_CODE);
    }
}

@Override
public void onRequestPermissionsResult(int requestCode, @NonNull String[] permissions, @NonNull int[] grantResults) {
    super.onRequestPermissionsResult(requestCode, permissions, grantResults);
    if (requestCode == REQUEST_CODE) {
        if (grantResults.length == 1 && grantResults[0] == PackageManager.PERMISSION_GRANTED) {
            showHomeFragment();
        } else {
            // Permission was not granted
        }
    }
}

private void showHomeFragment() {
    HomeFragment fragment = new HomeFragment();
    getSupportFragmentManager()
            .beginTransaction()
            .replace(R.id.root_container, fragment)
            .commit();
}

---

您需要做的是：授予权限后，打开

@Override
public void onRequestPermissionsResult(int requestCode,
    String permissions[], int[] grantResults) {
switch (requestCode) {
    case READ_EXTERNAL_STORAGE: {
        // If request is cancelled, the result arrays are empty.
        if (grantResults.length > 0
            && grantResults[0] == PackageManager.PERMISSION_GRANTED) {
            // permission was granted
            HomeFragment fragment = new HomeFragment();
            FragmentTransaction transaction = getSupportFragmentManager().beginTransaction();
            transaction.replace(R.id.root_container, fragment).commit();
        } else {

            // permission denied, boo! Disable the
            // functionality that depends on this permission.

        }
        return;
    }
}

---

请按照以下示例说明是否授予了检查权限。

其中是

onPermissionResult

？如果可能，发布所需的代码。请检查更新后的代码，如果可能，建议任何替代方法以实现所需的功能。@AshutoshPatoa您仍然缺少onPermissionResult方法。该方法将使用权限对话框的结果数据进行调用。我对此不太了解。请您解释一下我如何实现该方法？看起来您对运行时权限有点不清楚。请遵循此步骤，谢谢您的回答。现在我知道了我的代码到底缺少了什么。

@Override
public void onRequestPermissionsResult(int requestCode,
    String permissions[], int[] grantResults) {
switch (requestCode) {
    case READ_EXTERNAL_STORAGE: {
        // If request is cancelled, the result arrays are empty.
        if (grantResults.length > 0
            && grantResults[0] == PackageManager.PERMISSION_GRANTED) {
            // permission was granted
            HomeFragment fragment = new HomeFragment();
            FragmentTransaction transaction = getSupportFragmentManager().beginTransaction();
            transaction.replace(R.id.root_container, fragment).commit();
        } else {

            // permission denied, boo! Disable the
            // functionality that depends on this permission.

        }
        return;
    }
}